The ability of the terpyridine ligand to stabilize alkyl complexes of nickel has been central in obtaining a fundamental understanding of the key processes involved in alkyl-alkyl cross-coupling reactions. Here, mechanistic studies using isotopically labeled (TMEDA)NiMe(2) (TMEDA = N,N,N',N'-tetramethylethylenediamine) have shown that an important catalyst in alkyl-alkyl cross-coupling reactions, (tpy')NiMe (2b, tpy' = 4,4',4' '-tri-tert-butylterpyridine), is not produced via a mechanism that involves the formation of methyl radicals. Instead, it is proposed that (terpyridine)NiMe complexes arise via a comproportionation reaction between a Ni(II)-dimethyl species and a Ni(0) fragment in solution upon addition of a terpyridine ligand to (TMEDA)NiMe(2). EPR and DFT studies on the paramagnetic (terpyridine)NiMe (2a) both suggest that the unpaired electron resides heavily on the terpyridine ligand and that the proper electronic description of this nickel complex is a Ni(II)-methyl cation bound to a reduced terpyridine ligand. Thus, an important consequence of these results is that alkyl halide reduction by (terpyridine)NiR(alkyl) complexes appears to be substantially ligand based. A comprehensive survey investigating the catalytic reactivity of related ligand derivatives suggests that electronic factors only moderately influence reactivity in the terpyridine-based catalysis and that the most dramatic effects arise from steric and solubility factors.

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9needed; these are often laborious and not practical for high-throughput screening. In order to develop a rapid automated mutation detection method, we have evaluated denaturing high-performance liquid chromatography for detection of TP53 mutations in tumor tissue. The specificity and sensitivity of the method were compared to those of denaturing gradient gel electrophoresis through testing on standard-quality DNA preparations as well as on DNA extracted from formalin-fixed, paraffin-embedded tissue sections. Amler, Lukas[8]Functional dissection of transcriptional profiles in androgen-dependent andindependent prostate cancer Using microarray analysis, we have measured changes in gene expression that occurred during the evolution of a primary prostate cancer xenograft, CWR22, from normalcy to relapsed, androgen-independent growth following androgen deprivation therapy. Rather than relying on simple pairwise comparison of the data between successive biological states (for example, normal versus tumor), we clustered the expression data on the basis of behavior in multiple biological states, representative of the entire process of prostate cancer progression. By examining the data in the context of different proliferative conditions, before and after hormonal manipulation in the xenograft model, we could identify groups of genes associated with proliferation, metabolism, hormone responsiveness and malignant transformation, as well as a small number of genes directly associated with androgen-independent growth. Our results imply that the evolution to androgen independence is due, in part, to reactivation of the androgen-response pathway in the absence of androgens, but that this reactivation is probably incomplete. Amler, Lukas [9]Dysregulated expression of androgenresponsive and nonresponsive genes in the androgen-independent prostate cancer xenograft model, CWR22-R Treatment of metastatic prostate cancer with androgen ablation often elicits dramatic tumor regressions, but the response is rarely complete, making clinical recurrence inevitable with time. To gain insight into therapy-related progression, we used microarray analysis to monitor changes in gene expression that occurred following androgen starvation of an androgen-dependent prostate tumor xenograft, CWR22, and the emergence of an androgen-independent tumor, CWR22-R. Androgen deprivation arrested the growth of CWR22 cells, as evidenced by decreased expression of genes encoding cell cycle components and basal cell metabolism, respiration and transcription, as well as the induced expression of putative negative regulatory genes that may act to sustain cells in a nonproliferative state. Evolution of androgen-independent growth and proliferation, represented by CWR22-R, was associated with a re-entry into the active cell cycle and the upregulation of several genes that were expressed at low levels or absent in the androgen-dependent tumor. Restoration of androgen to mice bearing androgenindependent CWR22-R tumors induced, augmented or repressed the expression ...

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